If so then that's easy. In GIMP, open your diff map and bump map (as two layers in the same canvas). If you didn't export the spec map with the diff and bump, then you'll have to remove the specular mask from the diff map's alpha channel. For that, select the layer, then right-click, add layer mask, transfer layer's alpha channel, then right click and delete layer mask.

After you've got your diff map ready, select its layer and go to Filters > Map > Bump map. Then in the drop-down menu where you select which map you want to use for the bump, select your bump map (should be right next to the diff map since you opened them at the same time). Then play with the settings until you have something you like.

You really should use a more advanced image editing program like GIMP so that you have the ability to create and manipulate layer masks. Surfaces are transparent, or partially so, so that they can carry specular reflection data in the alpha channel (i.e. the alpha channel is a specular map). The best way to use these maps would be to use GIMP and to create a layer mask for that map, and transfer the layer's alpha channel to the mask. Then you can toggle the mask as you like to see the surface, delete the mask altogether to eliminate the alpha channel, or even extract it into a new layer to save as a separate map.

I'd kill to have a video tutorial on that. Is that too much to ask for, though?

...it might be to your benefit if you say what exactly you need help with. Posts like this are a waste of time, both yours and everyone else's, and are against forum rules.

And you already mentioned a problem in another thread a few months ago, and I responded to you there, and you did not reply. If this is about the same problem, you should follow the instructions I already gave you previously, since I can't help you any further until you do.

Few things that I notice differs from the skybox to the screenshot: - No bloom - No atmospheric perspective (horizon haze, if that's how it's called?) - Terrain gets back in LOD -2 details, which TBH defeats the meaning of exporting the skybox - No detailled textures

I've never exported skyboxed from up close, so I actually never noticed that ...

Come to think of it now I remember that skybox export does have issues with planetary LOD, it is pretty frustrating... keep in mind though that he probably designed the skybox exporter to export space scenes rather than surface scenes, so more work is probably needed to make it work well on planets.

I'm using SpaceEngine to produce skyboxes for a mod, and I've run into a bit of a snag. In some cases the best views involve some exposure adjustments, but the exported skybox don't respect my exposure settings. I can use an image editor to aproximate it, but that produces noticeable artifacts that are pretty unsightly. Is there any way around this, or prospect of the situation changing in future versions?

The other thing that'd be nice is if I could turn galaxies off without also disabling the rendering of nebulae at the same time.